#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Project    : flask-tutorial
# @Author     : wangc
# @CreateTime : 2019/4/9 14:06
# @File       : blog

from flask import (
    Blueprint, flash, g, redirect, render_template, request, url_for
)
from werkzeug.exceptions import abort
from .auth import login_required
from .db import get_db

bp = Blueprint('blog', __name__)


@bp.route('/')
def index():
    db = get_db()
    posts = db.execute(
        """SELECT p.id, title, body, created, author_id, username
                FROM post p JOIN user u ON p.author_id = u.id
           ORDER BY created DESC 
        """
    ).fetchall()
    return render_template('blog/index.html', posts=posts)


@bp.route('/create', methods=('GET', 'POST'))
@login_required
def create():
    if request.method == 'POST':
        title = request.form['title']
        body = request.form['body']
        error = None

        if not title:
            error = '标题必输'

        if error is not None:
            flash(error)
        else:
            db = get_db()
            db.execute(
                """INSERT INTO post (title, body, author_id)
                        VALUES (?, ?, ?)
                """, (title, body, g.user['id'])
            )
            db.commit()
            return redirect(url_for('blog.index'))

    return render_template('blog/create.html')


def get_post(id, check_author=True):
    post = get_db().execute(
        """SELECT p.id, title, body, created, author_id, username
                FROM post p JOIN user u ON p.author_id=u.id
            WHERE p.id = ?
        """, (id,)
    ).fetchone()

    # abort() 会引发一个特殊的异常，返回一个 HTTP 状态码。
    if post is None:
        abort(404, '帖子ID {0} 不存在'.format(id))

    if check_author and post['author_id'] != g.user['id']:
        abort(403)

    return post


# update 函数有一个 id 参数。该参数对应路由中 的 <int:id>
@bp.route('/<int:id>/update', methods=('GET', 'POST'))
@login_required
def update(id):
    post = get_post(id)

    if request.method == 'POST':
        title = request.form['title']
        body = request.form['body']
        error = None

        if not title:
            error = '标题必输'

        if error is not None:
            flash(error)
        else:
            db = get_db()
            db.execute(
                "UPDATE post SET title=?, body=? WHERE id=?", (title, body, id)
            )
            db.commit()
            return redirect(url_for('blog.index'))

    return render_template('blog/update.html', post=post)


@bp.route('/<int:id>/delete', methods=('GET', 'POST'))
@login_required
def delete(id):
    get_post(id)
    db = get_db()
    db.execute('DELETE FROM post WHERE id = ?', (id,))
    db.commit()
    return redirect(url_for('blog.index'))
